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ReDoS
A regular expression denial of service (ReDoS) is an algorithmic complexity attack that produces a denial-of-service by providing a regular expression and/or an input that takes a long time to evaluate. The attack exploits the fact that many regular expression implementations have super-linear worst-case complexity; on certain regex-input pairs, the time taken can grow polynomially or exponentially in relation to the input size. An attacker can thus cause a program to spend substantial time by providing a specially crafted regular expression and/or input. The program will then slow down or become unresponsive. Description Regular expression ("regex") matching can be done by building a finite-state automaton. Regex can be easily converted to nondeterministic automata (NFAs), in which for each state and input symbol, there may be several possible next states. After building the automaton, several possibilities exist: * the engine may convert it to a deterministic finite-stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algorithmic Complexity Attack
An algorithmic complexity attack (ACA) is a form of attack in which an attacker sends a pattern of requests to a computer system that triggers the Best, worst and average case, worst-case performance of the algorithms it uses. In turn, this may exhaust the resources the system uses. Examples of such attacks include ReDoS, ReDOS, Zip bomb, zip bombs and Billion laughs attack, exponential entity expansion attacks. References Related works * * * Vahidi, Ardalan. “Crowdsourcing Phase and Timing of Pre-Timed Traffic Signals in the Presence of Queues: Algorithms and Back-End System Architecture.” Ieeexplore, 1 Nov. 2019, https://ieeexplore.ieee.org/abstract/document/7323843. * Kiner, Emil, and Satya Konduru. “How Google Cloud Blocked the Largest Layer 7 DDoS Attack yet, 46 Million Rps.” ''Google Cloud Blog'', 18 Aug. 2022cloud.google.com/blog/products/identity-security/how-google-cloud-blocked-largest-layer-7-ddos-attack-at-46-million-rps Algorithmic complexity att ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RE2 (software)
RE2 is a software library which implements a regular expression engine. It uses finite-state machines, in contrast to most other regular expression libraries. RE2 supports a C++ interface. RE2 was implemented by Google and Google uses RE2 for Google products. RE2 uses an "on-the-fly" deterministic finite-state automaton algorithm based on Ken Thompson's Plan 9 grep. Comparison to PCRE RE2 performs comparably to Perl Compatible Regular Expressions (PCRE). For certain regular expression operators like , (the operator for alternation or logical disjunction) it is superior to PCRE. Unlike PCRE, which supports features such as lookarounds, backreferences and recursion, RE2 is only able to recognize regular languages due to its construction using the Thompson DFA algorithm. It is also slightly slower than PCRE for parenthetic capturing operations. PCRE can use a large recursive stack with corresponding high memory usage and result in exponential runtime on certain patterns ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regular Expression
A regular expression (shortened as regex or regexp), sometimes referred to as rational expression, is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation. Regular expression techniques are developed in theoretical computer science and formal language theory. The concept of regular expressions began in the 1950s, when the American mathematician Stephen Cole Kleene formalized the concept of a regular language. They came into common use with Unix text-processing utilities. Different syntaxes for writing regular expressions have existed since the 1980s, one being the POSIX standard and another, widely used, being the Perl syntax. Regular expressions are used in search engines, in search and replace dialogs of word processors and text editors, in text processing utilities such as sed and AWK, and in lexical analysis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denial-of-service Attacks
In computing, a denial-of-service attack (DoS attack) is a cyberattack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to a network. Denial of service is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled. The range of attacks varies widely, spanning from inundating a server with millions of requests to slow its performance, overwhelming a server with a substantial amount of invalid data, to submitting requests with an illegitimate IP address. In a distributed denial-of-service attack (DDoS attack), the incoming traffic flooding the victim originates from many different sources. More sophisticated strategies are required to mitigate this type of attack; simply attempting to block a single source is insuffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Orbit Ion Cannon
High Orbit Ion Cannon (HOIC) is an open-source network stress testing and denial-of-service attack application designed to attack as many as 256 URLs at the same time. It was designed to replace the Low Orbit Ion Cannon which was developed by Praetox Technologies and later released into the public domain. The security advisory for HOIC was released by Prolexic Technologies in February 2012. Development HOIC was developed during the conclusion of Operation Payback by the hacktivist collective Anonymous. As Operation Payback concluded there was massive pressure on the group from law enforcement agencies, which captured and prosecuted more than 13 individuals connected with the group. This forced many members of the group to rethink their strategies and subsequently this part of the group launched Operation Leakspin. However a large part of Anonymous remained focused on launching opt-in DDoS attacks. However the Low Orbit Ion Cannon was not powerful enough to launch attacks wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Orbit Ion Cannon
Low Orbit Ion Cannon (LOIC) is an open-source network stress testing and denial-of-service attack application written in C#. LOIC was initially developed by Praetox Technologies, however it was later released into the public domain and is currently available on several open-source platforms. Characteristics LOIC performs a DoS attack (or, when used by multiple individuals, a DDoS attack) on a target site by flooding the server with TCP, UDP, or HTTP packets with the intention of disrupting the service of a particular host. People have used LOIC to join voluntary botnets. The software inspired the creation of an independent JavaScript version called ''JS LOIC'', as well as a LOIC-derived web version called ''Low Orbit Web Cannon''. These enable a DoS from a web browser. Countermeasures Security experts quoted by the BBC indicated that well-written firewall rules can filter out most traffic from DDoS attacks by LOIC, thus preventing the attacks from being fully effec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denial-of-service Attack
In computing, a denial-of-service attack (DoS attack) is a cyberattack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to a network. Denial of service is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled. The range of attacks varies widely, spanning from inundating a server with millions of requests to slow its performance, overwhelming a server with a substantial amount of invalid data, to submitting requests with an illegitimate IP address. In a distributed denial-of-service attack (DDoS attack), the incoming traffic flooding the victim originates from many different sources. More sophisticated strategies are required to mitigate this type of attack; simply attempting to block a single source is insuffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denial-of-service
In computing, a denial-of-service attack (DoS attack) is a cyberattack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to a network. Denial of service is typically accomplished by flooding the targeted machine or resource with superfluous requests in an attempt to overload systems and prevent some or all legitimate requests from being fulfilled. The range of attacks varies widely, spanning from inundating a server with millions of requests to slow its performance, overwhelming a server with a substantial amount of invalid data, to submitting requests with an illegitimate IP address. In a distributed denial-of-service attack (DDoS attack), the incoming traffic flooding the victim originates from many different sources. More sophisticated strategies are required to mitigate this type of attack; simply attempting to block a single source is insufficie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algorithmic Complexity Attacks
Algorithmic may refer to: *Algorithm, step-by-step instructions for a calculation ** Algorithmic art, art made by an algorithm ** Algorithmic composition, music made by an algorithm **Algorithmic trading, trading decisions made by an algorithm ** Algorithmic patent, an intellectual property right in an algorithm * Algorithmics, the science of algorithms **'' Algorithmica'', an academic journal for algorithm research **Algorithmic efficiency In computer science, algorithmic efficiency is a property of an algorithm which relates to the amount of computational resources used by the algorithm. Algorithmic efficiency can be thought of as analogous to engineering productivity for a repea ..., the computational resources used by an algorithm ** Algorithmic information theory, study of relationships between computation and information ** Algorithmic mechanism design, the design of economic systems from an algorithmic point of view ** Algorithmic number theory, algorithms for number-theor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyberwarfare
Cyberwarfare is the use of cyberattack, cyber attacks against an enemy State (polity), state, causing comparable harm to actual warfare and/or disrupting vital computer systems. Some intended outcomes could be espionage, sabotage, propaganda, Internet manipulation, manipulation or economic warfare. There is significant debate among experts regarding the definition of cyberwarfare, and even if such a thing exists. One view is that the term is a misnomer since no cyber attacks to date could be described as a war. An alternative view is that it is a suitable label for cyber attacks which cause physical damage to people and objects in the real world. Many countries, including the United States, United Kingdom, Russia, China, Israel, Iran, and North Korea, have active cyber capabilities for offensive and defensive operations. As states explore the use of cyber operations and combine capabilities, the likelihood of physical confrontation and violence playing out as a result of, or p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oracle Corporation
Oracle Corporation is an American Multinational corporation, multinational computer technology company headquartered in Austin, Texas. Co-founded in 1977 in Santa Clara, California, by Larry Ellison, who remains executive chairman, Oracle was the List of the largest software companies, third-largest software company in the world in 2020 by revenue and market capitalization. The company's 2023 ranking in the Forbes Global 2000, ''Forbes'' Global 2000 was 80. The company sells Database, database software, particularly Oracle Database, and cloud computing. Oracle's core application software is a suite of enterprise software products, such as enterprise resource planning (ERP) software, human capital management (HCM) software, customer relationship management (CRM) software, enterprise performance management (EPM) software, Customer Experience Commerce (CX Commerce) and supply chain management (SCM) software. History Larry Ellison, Bob Miner, and Ed Oates co-founded Oracle in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
